Two completely different towns, and at the opposite ends of the economic scale. Whistable house prices are, well, pricey, whilst Margate are a lot cheaper (although increasing).
Whistable is a nice little town, that gets busy with tourists. It also has a shingles beach. It’s full of character.
Margate was considered a dump in the past, but has improved. It has a huge sandy beach and the seafront shops are quite nice now. Further away from the seafront, it’s not so well re-generated. The Turner exhibition and Dreamland has boosted the economy.
What is it you’re looking for?